This invention relates to magazines for semi-automatic firearms characterized by heavy recoil, such as 0.45 caliber and 9 mm pistols and, more particularly, to improvements in such magazines for accurately guiding or controlling the cartridge being fed by the spring follower to the uppermost position in the magazine.
With the advent, in recent years, of more compact high powered handguns, such as 0.45 caliber, 9 mm and 10 mm semi-automatic pistols, incidences of cartridge feed malfunctioning or jamming have markedly increased. It has been postulated that this problem is caused, during recoil of the gun, by increased velocity of the slide which, upon impacting against the frame, results in greater inertia being imparted to the cartridges carried in the magazine. The result is that the cartridges tend to shift forward in the magazine such that the uppermost cartridge may not be properly oriented for accurate feeding into the bore of the gun.
Although this particular problem has not been addressed, suggestions are found in the prior art of controlling the feed of the upper cartridge from the magazine into the chamber or bore of the firearm. U.S. Pat. No. 1,158,981 to Carl discloses the use of a pair of parallel, laterally spaced arms 21 to engage the body of the cartridge to guide the longitudinal movement thereof forward of the feed lips or flanges 31 into the bore. These arms do not, however, serve to guide or control the vertical upward movement of the cartridges within the magazine, as is accomplished by this invention.
U.S. Pat. No. 3,711,981 to Seecamp discloses a box-magazine provided with integral knock-out fingers 14 which have inwardly bent projections 15 which are adapted to engage the extractor grooves of all the cartridges in the magazine to prevent soft-nosed bullets being damaged by impacting against the front wall of the magazine because of recoil. While Seecamp deals with the problem of damage to the soft-nosed bullets, this invention relates to controlling the position or upward movement of the one cartridge being fed to the uppermost position in the magazine for accurate introduction into the bore of the firearm.
It is the principal object of this invention to provide a simple, effective, durable and form-stable guide member which projects inwardly from each of opposed sidewall portions of the magazine to control and hold the uppermost cartridge against inertial forward motion imparted by recoil and to guide the upward movement of cartridges to the uppermost position in the magazine by engagement with the extractor groove of the cartridge advancing from the penultimate to the uppermost position.
It is another object of this invention to form the guide members, as above-described, by lancing but not cutting through the side walls of the magazine to form guide members, each having an upright, rear edge portion and tapered inner surface portion comparable to the cross-section of the cartridge extractor groove.
It is a further object of this invention to provide a guide member of the above type in which the rear edge portion of the guide member is disposed at an oblique angle in the magazine to serve as a cam surface for corrective rearward movement of cartridges advancing vertically in engagement therewith.
The above and other objects of this invention will be more apparent from the following description read in conjunction with the accompanying drawings in which: